This document contains the release notes for the LLVM compiler
infrastructure, release 1.3. Here we describe the status of LLVM, including any
known problems and bug fixes from the previous release. The most up-to-date
version of this document can be found on the LLVM 1.3 web site. If you are
not reading this on the LLVM web pages, you should probably go there because
this document may be updated after the release.

For more information about LLVM, including information about potentially more
current releases, please check out the main
web site. If you have questions or comments, the LLVM developer's mailing
list is a good place to send them.

Note that if you are reading this file from CVS, this document applies
to the next release, not the current one. To see the release notes for
the current or previous releases, see the releases page.

This is the fourth public release of the LLVM compiler infrastructure. This
release primarily improves the performance of the
code produced by all aspects of the LLVM compiler, adds many new features, fixes a few
bugs, speeds up the compiler, and introduces a new (experimental)
PowerPC code generator.

At this time, LLVM is known to correctly compile and run all C & C++
SPEC CPU95 & 2000 benchmarks, the Olden benchmarks, and the Ptrdist
benchmarks, and many other programs. LLVM now also works
with a broad variety of C++ programs.

PowerPC-based Mac OS X boxes, running 10.2 and above. Note that no JIT
support is available yet, and LLC support is beta. The C backend can be used
to produce stable code for this platform.

The core LLVM infrastructure uses
GNU autoconf to adapt itself
to the machine and operating system on which it is built. However, minor
porting may be required to get LLVM to work on new platforms. We welcome your
portability patches and reports of successful builds or error messages.

Note that the LLVM build system does not currently support directories with
spaces on them when running on Win32/cygwin. We strongly recommend running
LLVM and the C frontend out of a top-level directory without spaces (e.g.,
/cygdrive/c/llvm). Also, make sure to install all of the
cygwin packages. By default, many important tools are not installed that
are needed by the LLVM build process or test suite (e.g., /bin/time). Finally,
please make sure that there are no directories with spaces in them in your
PATH environment variable.

This section contains all known problems with the LLVM system, listed by
component. As new problems are discovered, they will be added to these
sections. If you run into a problem, please check the LLVM bug database and submit a bug if
there isn't already one.

The following components of this LLVM release are either untested, known to
be broken or unreliable, or are in early development. These components should
not be relied on, and bugs should not be filed against them, but they may be
useful to some people. In particular, if you would like to work on one of these
components, please contact us on the llvmdev list.

The PowerPC backend is incomplete and is known to miscompile several SPEC
benchmarks. The file llvm/lib/Target/PowerPC/README.txt has
details.

The following passes are incomplete or buggy: -pgmdep, -memdep,
-ipmodref, -cee

The -pre pass is incomplete (there are cases it doesn't handle that
it should) and not thoroughly tested.

The following GCC extensions are partially supported. An ignored
attribute means that the LLVM compiler ignores the presence of the attribute,
but the code should still work. An unsupported attribute is one which is
ignored by the LLVM compiler and will cause a different interpretation of
the program.

Variable Length:
Arrays whose length is computed at run time.
Supported, but allocated stack space is not freed until the function returns (noted above).

Other Builtins:
Other built-in functions.
We support all builtins which have a C language equivalent (e.g.,
__builtin_cos), __builtin_alloca,
__builtin_types_compatible_p, __builtin_choose_expr,
__builtin_constant_p, and __builtin_expect
(currently ignored). We also support builtins for ISO C99 floating
point comparison macros (e.g., __builtin_islessequal).

For this release, the C++ front-end is considered to be fully functional but
has not been tested as thoroughly as the C front-end. It has been tested and
works for a number of non-trivial programs, but there may be lurking bugs.
Please report any bugs or problems.

IA-64 specific: The C++ front-end does not use IA64 ABI compliant layout of v-tables.
In particular, it just stores function pointers instead of function
descriptors in the vtable. This bug prevents mixing C++ code compiled with
LLVM with C++ objects compiled by other C++ compilers.

The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
parser is significantly more standards compliant (and picky) than prior GCC
versions. For more information, see the C++ section of the GCC 3.4 release notes.

Destructors for local objects are not always run when a longjmp is
performed. In particular, destructors for objects in the longjmping
function and in the setjmp receiver function may not be run.
Objects in intervening stack frames will be destroyed, however (which is
better than most compilers).

The LLVM C++ front-end follows the Itanium C++ ABI.
This document, which is not Itanium specific, specifies a standard for name
mangling, class layout, v-table layout, RTTI formats, and other C++
representation issues. Because we use this API, code generated by the LLVM
compilers should be binary compatible with machine code generated by other
Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
However, the exception handling mechanism used by LLVM is very
different from the model used in the Itanium ABI, so exceptions will not
interact correctly.

A wide variety of additional information is available on the LLVM web page,
including mailing lists and publications describing algorithms and components
implemented in LLVM. The web page also contains versions of the API
documentation which is up-to-date with the CVS version of the source code. You
can access versions of these documents specific to this release by going into
the "llvm/doc/" directory in the LLVM tree.

If you have any questions or comments about LLVM, please feel free to contact
us via the mailing
lists.